In order to optimize the efficiency of multi-phase converters, auto-phase shedding (also known as phase-cut) is usually required. In phase-cut mode, the number of switching circuits under power operation is determined by the magnitude of load current. When the load current is small, only part of the switching circuits in the multi-phase converter work and transfer energy to the load. However, if the load current rises instantaneously at this time, due to the time delay caused by ripple filtering in load current sensing, the multi-phase converter will not be able to respond in time, resulting in a large undershoot at the output voltage.